Exploring Database Systems

What is a relational database?

• A relational database is a collection of unstructured data.

• A relational database is a type of cloud storage service.

• A relational database is a software application for managing emails.

• A relational database is a database that organizes data into tables with defined relationships between them.

Define primary key in a relational database.

• A primary key is a foreign key in another table.

• A primary key is a unique identifier for a record in a relational database table.

• A primary key is an optional field in a database record.

• A primary key can have duplicate values in a table.

What is SQL and what is its purpose?

• SQL is a type of spreadsheet software.

• SQL is primarily used for graphic design.

• SQL is a programming language used for managing and manipulating relational databases.

• SQL is a markup language for web development.

Write a SQL query to select all records from a table named 'Students'.

• SELECT * FROM Students;

• SELECT Students WHERE 1=1;

• GET * FROM Students;

• SELECT ALL FROM Students;

Explain the concept of database normalization.

• Database normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Database normalization is the technique of merging all tables into one large table.

• Database normalization is the process of deleting all data from a database.

• Database normalization refers to the method of increasing redundancy in data storage.

What are the different normal forms in database normalization?

• 1NF, 2NF, 3NF, BCNF, 4NF, 5NF

• 1NF, 2NF, 3NF, 6NF

• 1NF, 2NF, 3NF, 4NF, 7NF

• 1NF, 2NF, 3NF, 4NF, 5NF, 6NF

What is an entity in an Entity-Relationship model?

• An entity is a collection of attributes that describe a thing.

• An entity is a type of relationship between two objects.

• An entity is a distinct object or thing in the real world that can be identified.

• An entity is a process that occurs in a system.

How do you represent relationships in an ER diagram?

• Relationships are shown as lines without any symbols in an ER diagram.

• Relationships are represented by diamonds connecting entities in an ER diagram.

• Relationships are depicted using rectangles in an ER diagram.

• Relationships are represented by circles in an ER diagram.

What is the purpose of database security measures?

• To reduce the size of the database files.

• To protect sensitive data from unauthorized access and ensure data integrity, confidentiality, and availability.

• To enhance the speed of database queries.

• To improve the aesthetic design of the database interface.

Name three common database security measures.

• Data backups

• User training

• 1. Access controls 2. Encryption 3. Regular updates and patches

• Network firewalls